1. Field of the Invention
The present invention is broadly concerned with improved, high-speed labeling devices of the type used to label an array of packages in the context of form, fill and seal packaging machines or other types of package thermoforming devices. More particularly, the invention is concerned with such labelers and methods of operation thereof wherein a plurality of labels are dispensed as a group in a “burst” fashion, thereby eliminating time-consuming iterative stop-and-start of the labeler.
2. Description of the Prior Art
U.S. Pat. No. 6,543,505 describes highly successful labeling devices designed to apply labels on-line to packages in form, fill and seal thermoform packaging machines. The devices of the ′505 patent are capable of using labels of a single roll and to apply the labels at a 90 degree angle to any package array. The device uses separate stepper motors for label web advancement and label peeling, for transporting, separating and applying the labels, and for selectively indexing the entire system to label multiple rows.
U.S. Pat. No. 6,868,887 describes further improvements in transverse labeling devices, with provision of an improved label tamper assembly which largely eliminates label fouling during operations.
The labelers described in the ′505 and ′887 patents are designed to dispense labels in a stepwise, distance-based, stop-and-start fashion. In particular, when a plurality of labels are to be dispensed, the label dispensing unit and label transport belt are operated intermittently in order to ensure accurate label location across the labeler. This type of operation is capable of very accurate label positioning; however, it is a relatively slow process, and indeed label dispensing in these units constitutes the rate-limiting step both of the labeler and sometimes of the entire packaging device.
U.S. Pat. No. 6,558,490 describes apparatus which dispenses labels continuously in a non-stop fashion. However, the labels are applied directly, one at a time onto packages in an in-line configuration. The speed of the dispenser is adjusted continuously between labels to match the random timing of products, so that products and labels meet simultaneously at an application point. U.S. Pat. No. 4,324,608 poses the concern of spacing labels prior to the advent of modern motion control systems. The patent describes use of mechanical stops to set the final positions of labels. U.S. Pat. No. 4,046,613 also describes older concept wherein labels are dispensed on a transporter and a moveable sensor is used to initiate operation of the label dispenser to set the position of the labels. In this design, the transporter and labeler head run at the same speed and label dispensing occurs intermittently, based upon reception of the sensor signal. Finally, U.S. Pat. No. 3,871,943 relates to a bottle labeler using a turret applicator.
There is accordingly a real and unsatisfied need in the art for an improved transverse labeling device designed to rapidly dispense a plurality of labels as a group in a “burst” manner, thereby eliminating the conventional stop-and-start operation of current labelers. It is possible that other workers in the art have attempted to provide such high-speed labeling devices.